Such a kind of vehicular electronic device has, for example, a microcomputer and controls several devices (sensor and actuator). Recently, a vehicular control device has been electronized. For example, not only a conventional navigation function but also various services such as cooperation with an external center or control of a vehicle behavior have been put into practice.
To put such various controls into practice, the number of semiconductor packages equipped to a board increases. To equip the semiconductor packages to a multilayer wiring board, solder is formed on electrode pads disposed on the multilayer wiring board and a component is mounted thereon (for example, see patent literature 1).
According to an art described in patent literature 1, an electrode pad has a laterally-long shape. A solder resist covers an upper end of the electrode pad and an opening is formed in the solder resist. A width of the opening of the solder resist is shorter than a width of the laterally-long shape of the electrode pad. A center of the opening is offset from a center of the laterally-long shape in a direction toward a center of an IC to be soldered. As a result, an occurrence of an operation failure caused by a solder crack due to a variation in temperature can be reduced in the multilayer wiring board to which the IC is flip-chip bonded.